MECA0500: FUEL CELLS - Part 1: Fuel Cell...Fuel Cell - History In 1839 Christian Schönbein, a...

MECA0500: FUEL CELLS - Part 1: Fuel Cell

Pierre Duysinx

LTAS-Automotive Engineering

University of Liege

Academic year 2018-2019

1

References

◼ C.C. Chan & K.T. Chau. Modern Electric Vehicle Technology. Oxford Sciences publications. 2001.

◼ M. Ehsani, Y. Gao, S. Gay & A. Emadi. Modern Electric, Hybrid Electric, and Fuel Cell Vehicles. Fundamentals, Theory, and Design. 2nd edition. CRC Press, 2010

◼ L. Guzzella & A. Sciaretta. Vehicle Propulsion Systems. Introduction to Modeling and Optimization. 3rd edition. Springer Verlag 2013.

◼ J. Larminie & A. Dicks. Fuel Cell Systems Explained. J. Wilez & sons. 2001.

◼ J. Pukrushpan, A. Stephanopoulou & H. Peng. Control of Fuel Cell Systems. Springer. 2004.

◼ Les Piles à Combustibles http://www.annso.freesurf.fr/index.html#plan

◼ Fuel cell org: www.fuelcell.org

2

http://www.annso.freesurf.fr/index.html#plan

http://www.fuelcell.org/

Introduction

3

Energy: A sustainable approach

◼ Reduction of the energy consumption

◼ Reduction of the energy needs: modification of the way of life and energy consumption usage

◼ Combination of several energy usages

◼ Integrating the processes

◼ E.g. combined heat and electricity production

◼ Reduction of the energy losses

◼ Thermal insulation of buildings

◼ Reducing the friction losses

4

Energy: A sustainable approach

◼ Exploitation of alternative energy sources

◼ Alternative energy sources

◼ Biomass

◼ Waste (energy valorization of wastes : burning wastes, heat valorization of exhaust by burning gases)

◼ Solar energy

◼ Photovoltaic conversion

◼ Thermal conversion

◼ Wind energy

◼ Hydro-electric production

◼ Nuclear:

◼ A new start?

5

Improving the energy conversion efficiency

◼ Steam engine (1850): 3%

◼ Gas turbine (1945): 10%

◼ Internal combustion engine (1950): 20%

◼ Electric power plant (1960): 41%

◼ Turbine gas steam (1990): 51%

◼ Fuel cell (2000): 50%

◼ Solid Oxide FC + gas turbine (2005): 75%

6

Improving the energy conversion efficiency

◼ Question: direct conversion of chemical energy of the fuel into electricity

◼ Classical (thermodynamic) approach :

◼ Combustion

◼ Thermal engine

◼ Generator

◼ Efficiency limited by Carnot

◼ W = h H

◼ Carnot principle: h = 1- T0/T

7

Direct conversion

◼ Electrochemical systems

◼ Volta batteries:

◼ Closed system, irreversibility

◼ Consumption of the reactants chemicals

◼ Rechargeable batteries

◼ Closed system but reversible

◼ Regeneration of reactants

◼ Fuel Cells

◼ Open system

◼ Reactants are continuously provided, while reaction products are eliminated

8

Fuel Cell - History

◼ In 1839 Christian Schönbein, a German scientist discovers the fuel cell effects

◼ From 1839 to 1842, The Welsh scientist William Groove makes the first lab implementation of a fuel cell

◼ From 1932, F. Bacon restarts study of fuel cells and shows prototypes of 1 kW in 1953 and 5 kW in 1959.

◼ Thomas Grubb and Leonard Niedrach from GE brings new improvements related to the sulfonated membranes and the platinum deposition on electrodes ➔ Grubb-Niedrach

fuel cell will be the basis for space exploration fuel cells developed by NASA and Mac Donell Aircraft for Gemini program.

◼ The first hydrogen fuel cell application was made by Roger Billing in 1991.

9

W. Groove

Working principle of alkaline batteries

◼ Negative electrodes (anode)

◼ Oxidation of Zinc

◼ Zn + 2 OH- → Zn(OH)2 + 2 e-

◼ Positive electrode (cathode)

◼ Manganese dioxide MnO2

◼ MnO2 + 2 H2O + 2 e-→ Mn(OH)2 + 2 OH-

◼ Electrolyte

◼ Caustic potash

◼ KOH

10

What is a Fuel Cell?

◼ Direct conversion of the chemical fuel into electricity using a electrochemistry process

◼ Electrochemical reaction (oxidoreductase) without combustion(flame)

◼ Reactants are continuously fed, converted and then eliminated

◼ Reaction products are removed continuously

◼ Protons / ions are carried out from one electrode to the other one through the electrolyte (liquid or solid)

◼ Close to each electrode, highly conductive plates collect and drain the current to external circuit.

◼ Electrons that are exchanged during the reaction are conducted through the external electrical circuit.

11

Working principle of fuel cells

◼ The fuel: generally (di)hydrogen

◼ Oxidizer: oxygen (often from air)

◼ Hydrogen + Oxygen → water (steam) + electricity + heat

◼ Electricity: direct current

12

Working principle of H2 –O2 fuel cell

13


14


◼ At anode: oxidation of hydrogen (catalyzed reaction)

◼ H2 2 H+ + 2 e- Acid electrolyte

◼ H2 + 2 OH- 2 H2O + 2 e- Basic electrolyte

◼ At cathode, reductase of oxygen (catalyzed reaction)

◼ 1/2 O2 + 2 H+ + 2e- H2O Acid electrolyte

◼ 1/2 O2 + H2O + 2e- 2 OH- Basic electrolyte

◼ Balance

◼ H2 + 1/2 O2 H2O + heat

15

Work scheme of a single cell

Source: Schatz Energy Research Center

16


◼ The fundamental working principle is the inverse reaction of water electrolysis

◼ This chemical reaction is exothermic at 25 C.

◼ Free enthalpy of the reaction is -237 or -229 kJ/mol depending on the fact that the produced water is under liquid or gaseous form.

◼ This corresponds to theoretical voltages of 1,23 and 1,18 V. The voltage depends also of the temperature.

◼ The reaction requires the presence of catalyst (Pt or Pt/Ru) to activate (accelerate) the reaction speed.

17


◼ Every electrochemical systems require an electrolyte to transfer ions from one electrode to the other.

◼ For Proton Exchange Membrane (PEM) fuel cells

◼ Solid electrolyte

◼ Ions H+

◼ Polymer membrane (Nafion)

18


◼ Nafion is a sulfonated tetrafluoroethylene based fluoropolymer-copolymer discovered in the late 1960s by Walther Grot of DuPont.

◼ First of a class of synthetic polymers with ionic properties which are called ionomers.

◼ Nafion's unique ionic properties are the result of incorporated perfluorovinyl ether groups terminated with sulfonate groups onto a tetrafluoroethylene (Teflon)

19Source Wikipedia


◼ Advantages:

◼ Operating generally at low or moderate temperatures

◼ Silent operation

◼ High theoretical efficiency (hth~92%)

◼ Drawbacks:

◼ Cost of electrodes (Pt)

◼ Purity of fuel

◼ Limited power density

20

From MEA to single cell and fuel cell stack

21

Single fuel cell

22

◼ Mechanisms at electrodes:

◼ Reagents are brought by convection

◼ Diffusion towards the reaction anode sites through gas diffusion layer

◼ Reaction of H2 using catalyst

◼ Dissolution into the electrolyte

◼ Reaction H2-O2 using catalyst

◼ Diffusion of products towards the gaseous phase

◼ Elimination by convection

Single cell scheme

23

Membrane Electrode Assembly (MEA)

24

Membrane Electrode Assembly

◼ Considerable effort has been made in researching electro catalysts.

◼ To date, the best PEM fuel cell anode and cathode catalysts are still platinum-based.

◼ To maximize platinum utilization and minimize cost, platinum is finely dispersed on an electrically conducting, relatively chemically inert support such as a carbon black. In this manner the amount of active platinum exposed to the reactants is maximized, greatly increasing power density.

25Catalysts and catalyst layers

Membrane Electrode Assembly

◼ Secondary functions: minimize water flooding and maximize the electronic contact at the interface with the catalyst layer.

◼ The GDL serves in water management as it removes product water away from the catalyst layer.

◼ The GDL usually has a dual layer structure :

◼ 1/ A microporous layer next to the catalyst layer and made from carbon powder and a hydrophobic agent (PTFE).

◼ 2/ The second layer is a macroporous carbon substrate consisting of the carbon paper or cloth. 26

Gas Diffusion Layer

◼ The gas diffusion layer (GDL) or backing layer is a critical component in an MEA.

◼ GDL’s main function is to distribute the reactant gases while providing a good electronic conductivity, porous conductors such as carbon cloth or paper are commonly used.

Membrane Electrode Assembly (MEA)

◼ Anodes:

◼ Metal catalyst (Pt, Pd, Rh, etc.) supported on active C

◼ Ni of Raney (alkaline fuel cells)

◼ Fe, Co, Ni at high temperature (sintered metals or cermet)

◼ Cathodes:

◼ Precious metals at low temperature

◼ Ni sintered (or melted carbonates)

◼ Mixed oxides (high temperature fuel cells)

27

Gas distribution channels carved in the

current collectors (graphite)

gasketsCathodic catalytic

layer (Air)

Diffusion

layer

MEA: Membrane-Electrode Assembly

Membrane

Nafion®

Anodic catalytic

layer (H2)

Diffusion

layer

28

Design of Membrane Electrode Assembly (MEA)

Bipolar plates in carved graphite

Metal bipolar plates

Design

COST !

Design of Membrane Electrode Assembly

29

Fabrication of a single cell

30Exploded view of single PEM fuel cell.

Fabrication of a single cell

31

Assembly of a fuel cell stack

32


33

Exploded view of PEM fuel cell stack


◼ In practice, the single cells are stacked in parallel or serial assembly to shape a fuel cell stack.

◼ The fuel cell stack power depends on the number and the surface of fuel cells that are compiled.

◼ The range of power of the stack can span from a few W to several MW.

◼ One can find miniaturized fuel cell stacks of a few Watts.

34

Fuel cell systems

35

Schematic of hydrogen PEM fuel cell system.

Fuel cell systems

◼ Hydrogen reformer or hydrogen purification. Hydrogen gas rarely occurs naturally on the earth’s surface and has to be made from other chemical fuels. Once the hydrogen fuel is made, impurities such as carbon monoxide poisons the cell, necessitating purification and detection systems.

◼ Air supply. Oxidant must be supplied to the cathode at a specific pressure and flow rate. Air compressors, blowers, and filters are used for this.

◼ Water management. The inlet reactant gasses must be humidified, and the reaction produces water. Management of water must also consider relative amounts of the two phases.

◼ Thermal management. Stack temperature must be monitored and controlled through an active or passive stack cooling systems as well as a separate heat exchanger in the case of an active system.

36

Conversion efficiency of a Fuel Cell

37

Characteristics of an elementary fuel cell

◼ Work of the fuel cell = variation of free energy (Gibbs)

◼ Maximum voltage

◼ Example:

◼ DG = -229 kJ/mol H2(g) DG = -237 kJ/mol H2(l)

◼ Emax = 1,18 V Emax = 1,23 V

38


◼ The maximum voltage at the fuel cell depends also of the temperature. Indeed

◼ In case of a reduction of the number of molecules (case of fuel cells H2/O2), there is a reduction of entropy DS<0 and the absolute value of DG is reduced with the temperature.

◼ Example H2/O2

◼ 25°C: 1,18V 650°C: 1,02V 1000°C: 0,92V

39


◼ Energy efficiency

◼ Example

◼ DH = -242 kJ/mol (PCI)

◼ DG = -229 kJ/mol

◼ h = 95% à 25°C (74% à 1000°C)

◼ In practice the efficiency is inferior

40


Efficiency of the H2/O2 fuel cell compared to the Carnot efficiency (Tu=300K)

41


Polarization curve of the FC: voltage-current density curve

42


◼ Loss of efficiency due to over tension and polarization, and the reduction of voltage:

◼ Open Circuit losses: irreversibilites and non standard conditions.

◼ Operational losses: Activation losses, Ohmic losses, Concentration polarization

43


◼ Generally, on distinguishes three domains in the experimentalvoltage-current curves of FC. There are three main operational lossesare often referred to as

◼ Activation polarization: kinetic and irreversibility of reactions

◼ Ohmic losses: resistance of the ionic conduction

◼ Concentration polarization losses: mass transfer resistance of reactants and products

44

Polarization curve of the FC: voltage-current density curve


◼ 1/ Activation loss regime: Even for zero and very low currents, there are irreversible losses. These stem from the activation energy of the electrochemical reactions at the electrodes [mainly at cathode electrode (oxygen)].

◼ These losses depend on the reactions at hand, the electro-catalyst material and microstructure, reactant activities (and hence utilization), and weakly on current density. They are related to the energy required to initiate the reactions and the finite speed (kinetic) of electrochemical reactions.

◼ The activation losses related to charge transfer are ruled by the Butler Volmer law. This law can be approximated by the semi empirical Tafel law

◼ Or it’s empirical approximation

45


◼ 2/ Ohmic loss regime: For intermediate current density, where the FC is generally used, the losses increase linearly with the current density. It is typical from ohmic losses due to internal resistance of the ion current across the electrolyte and the membrane, and the electronic resistance in the electrodes, current collectors and interconnects, and contact resistances.

◼ Ohmic losses are proportional to the current density, depend on materials selection and stack geometry, and on temperature.

46


◼ 3/ Mass transfer loss regime: For high current densities, the losses increase drastically. The over tensions result from the finite mass transport limitations rates of the reactants and the products of the reaction to and from the electrodes. These losses depend strongly on the current density, reactant activity, and electrode structure. It is therefore also denominated as the concentration polarization.

◼ Concentration loss are generally expressed by the law

◼ Or alternatively

47


48

Loss of efficiency

◼ The reversible efficiency is calculated as the ratio between the theoretical (reversible) voltage and the actual voltage measured at the ports:

◼ This efficiency depends on the catalyst, the health state of electrodes, material selection, choice of oxidant (pure oxygen of from air), ambient conditions (temperature, pressure)

49

Loss of efficiency

◼ Faradic efficiency◼ Take care of the number of electrons actually participant to the

electrochemical reaction compared to the electrons liberated by the oxidoreductase per mole of fuel

◼ For hydrogen H2: efficiency is close to 1

◼ For methanol FC, one has secondary reactions (formaldehydes, formic acid) ➔ efficiency can drop to 0,66 or even 0,33

◼ Account also for internal short circuits

◼ Material efficiency◼ Take into account for the (uncompleted) usage of the input fuel at

the level of electrodes

◼ Generally one admits more than the stoichiometric fraction ratio of air (1,7) and of H2 (1,4)

◼ H2 is not fully utilized

50

Loss of efficiency

◼ System efficiency

◼ In mobile and stationary applications, the fuel cell does not work isolated.

◼ Several auxiliaries are necessary: air compressors, control systems, thermal control, reforming and purification of H2 (desulfuration, Hydrogen purification, heat exchangers)

◼ Generally they have a global efficiency of 80%

51

Global efficiency of the FC system

◼ Global efficiency of the fuel cell

◼ Numerical example H2/O2 @ 80°C, PEMFC with actual voltage of 0,7V for 350 mA/cm²

◼ Reversible efficiency (thermodynamics) : 0,936

◼ ➔ Electrical efficiency : 0,60

◼ Faradic efficiency: 1

◼ Material efficiency: 0,9

◼ System efficiency: 0,8

◼ Total: 40,4%

52

Fuel cell technologies

53


◼ One distinguishes 6 types of fuel cells:

◼ AFC: Alkaline Fuel Cell

◼ PEMFC: Polymer Exchange Membrane Fuel Cell

◼ DMFC: Direct Methanol Fuel Cell

◼ PAFC : Phosphoric Acid Fuel Cell

◼ MCFC: Molten Carbonate Fuel Cell

◼ SOFC: Solid Oxide Fuel Cell

54


◼ The different cell technologies are characterized by:

◼ The type of fuel: hydrogen, methanol, natural gas

◼ The nature of the electrolyte

◼ The kind of the transported ions: H+, OH- or carbonate

◼ The operating temperature

◼ The architecture of the fuel

◼ The size of the application (buildings, vehicle, electricity power plant, computer, portable communication equipment and by the nature of the application (mobile or stationary)

◼ The typical power range

◼ The conversion efficiency

◼ The technology maturity or technological readiness level (TRL)

◼ The cost per kW

55

Fuel cell technologiesFuel cell

name Electrolyte

Qualified

power

(W)

Working

temperature

(°C)

Efficiency

(cell)

Efficiency

(system) Status

Cost

(USD/W)

Direct

borohydride

fuel cell

Aqueous

alkaline

solution

70

Research

Alkaline

fuel cell

Aqueous

alkaline

solution

10 – 100

kW < 80 60–70% 62%

Commercial /

Research

Direct

methanol

fuel cell

Polymer

membrane

(ionomer)

100 mW

– 1 kW 90–120 20–30% 10–20%

Commercial /

Research

Reformed

methanol

fuel cell

Polymer

membrane

(ionomer)

5 W –

100 kW

250–300

(Reformer)

125–200

(PBI)

50–60% 25–40% Commercial /

Research

Proton

exchange

membrane

fuel cell

Polymer

membrane

(ionomer)

100 W –

500 kW

50–120

(Nafion)

125–220

(PBI)

50–70% 30–50% Commercial /

Research 30–35

Phosphoric

acid fuel cell

Molten

phosphoric

acid

(H3PO4)

< 10 MW 150-200 55%

40%

Co-Gen:

90%

Commercial /

Research 4–4.50

Molten

carbonate

fuel cell

Molten

alkaline

carbonate

100 MW 600-650 55% 47% Commercial /

Research

56

Low T Moderate T Medium T High T

100 200 600 800 1000 12000

AFC

PEMFC

DMFC

PAFC

MCFC

SOFC

DBFC


57


◼ Low temperature T (80-90°C)

◼ Proton Exchange membrane FC (PEM)

◼ Alkaline fuel cell (AFC)

◼ Direct methanol FC (DMFC)

◼ Moderate temperature (200°C)

◼ Phosphoric Acid FC (PAFC)

◼ Medium temperature(600-700°C)

◼ Melted Carbonate FC (MCFC)

◼ High temperature (900-1000°C)

◼ Solid Oxide FC (SOFC)

58

Piles alkaline fuel cells

◼ Electrolyte: KOH solution 30-45%

◼ Temperature 60-90°C at atmospheric pressure (T higher at higher pressure)

◼ Electrodes: Ni or Pt at anode and coal +Ag at cathode

◼ Fuel: H2 and oxidizer: O2

◼ Ions: OH-

◼ Power: 70-100 mW/cm²

◼ Low tolerance: a few ppm of CO and CO2 in H2 and air◼ CO is a poison of KOH → K2CO3

◼ Developed in Belgium by HYDROGENICS

◼ Examples of application: ◼ Spaceship vessels (Gemini, Apollo)

◼ Technological Readiness Level: industrial level

59

Polymer exchange membrane

◼ Temperature 60-100°C; pressure between 1 and 5 bars

◼ Fuel: H2 pure or from reforming - Oxidizer: O2 (air)

◼ Ions H+

◼ Electrolyte: conducting polymer membrane

◼ Thickness: 50-100µm

◼ Sulfonated tetrafluoroethylene based

fluoropolymer-copolymer (Nafion)

◼ High cost: 500€/m²

◼ Hygrometric constraint: water saturation

◼ Catalyst of anode: Pt (0,5 – 2 mg/cm²)

◼ Inter connection plate: graphite machine tooled

◼ Tolerant of a few ppm of CO

60

Polymer exchange membrane

◼ Power: 200-400 mW/cm²

◼ Examples of applications: vehicles, portable systems, cogeneration, marine

◼ Manufacturers: ex. Ballard (Canada), Horizon, MES…

◼ Development level : prototype or pre industrial level

◼ Prototypes 250 kW (env. 1kW / litre)

Application: Ballard250 kW + heatAlsthom, Promocell

61

Direct Methanol Fuel Cell

◼ Anode: methanol supply (CH3OH)

◼ Cathode: oxygen oxidizer (O2 )

◼ Temperature 60-100°C; pressure between 1 and 5 bars

◼ Fuel: methanol - Oxidizer: O2 (air)

◼ Ions H+

◼ Electrolyte: polymer exchange membrane

62


63


64


◼ Disadvantages:

◼ Activity of methanol is lower than H2

◼ Secondary reactions

◼ Lower efficiency than PEMFC with H2 ( 2/3 à 1/3!)

◼ Advantages:

◼ Methanol is liquid so that it is easier to transport, to store and to refuel compared to à H2 (gas)

◼ Applications: portable equipment (GSM, PC)

◼ TRL: prototype

65

Other H2 supply: PEM with methanol reforming

◼ Production of H2 from methanol using reforming

66

Other H2 supply: PEM with methanol reforming

67

PAFC: phosphoric acid fuel cells

◼ Electrolyte: phosphoric acid H3PO4 100%

◼ Temperature 180-220°C

◼ Fuel: H2 pure or from reforming - Oxidizer: O2 (air)

◼ Ions H+

◼ Power density: 100 – 300 mW/cm²

◼ Tolerance: 1% CO

◼ Applications: cogeneration

◼ TRL: mature technology

68


Géométrie d’une pile PAFC

69


A fuel cell O.N.S.I. of 200 kWe and 200 kWth was installed in

France in Celles by E.D.F. and G.D.F., for a demonstration project. It

consumes natural gas provided by G.D.F and provides electrical

energy as well as heat up to 80°C 70

MCFC: Molten Carbonate Fuel Cell

◼ Molten Carbonate Fuel Cell : K2CO3, Li2CO3 melted in a matrix of LiAlO2 (thickness 0,4 mm)

◼ Electrolytes: CO32-

◼ Fueling in H2 or natural gas CH4:

◼ Anode:

◼ Cathode:

◼ Regeneration loop of CO2 between anode and cathode

◼ Temperature : 600-660°C

◼ Catalysts:

◼ Anode: Ni + Cr

◼ Cathode: NiO + Li

◼ Connection plates made of Ni

71


◼ Tolerant to CO

◼ Corrosion problems

◼ Stationary applications for high powers (800 kW to 2 MW) : cogeneration, centralized production of electricity, marine applications

◼ TRL: prototypes pre-industrial

MCFC with reforming of methanol72


MCFC with internal reforming73


◼ Several advantages of MCFC

◼ High electrical efficiency (60%),

◼ Utilization of produced heat for cogeneration or internal reforming and combination with gas turbine,

◼ Possible to use fuels as methane, methanol, ethanol or gasified coal...

◼ Possible to use non precious metal as catalyst metals in electrodes.

74


Design of combined cycle (Ansaldo)75


Application: MCFC of 2MW in Santa Clara, California. Operation time: 4000h. Other system: MCPower system of 250 kW used as a cogeneration unit in Miramar, California (See figure)

76

Solid Oxide Fuel Cell : SOFC

◼ Conducting electrolyte: Zirconium doped with Yttrium: ZrO2 and Y2O3.

◼ Ions: O2-.

◼ Temperature: 700-1000°C

◼ Fuel: supply in pure H2 or from reforming, natural gas CH4, CO or other fossil fuel (very interesting)

◼ Oxidizer: O2 (air)

◼ Reactions:

◼ Anode:

◼ Cathode

77


◼ Stationary and mobile application

◼ Vast application power (2,5 kW to 100 MW)

◼ Technical difficulties

◼ Corrosion

◼ Materials : fragile behavior and sensitivity w.r.t. to thermal shocks

◼ Reduction of voltage with temperature T

◼ TRL: prototypes

78


SOFC Fuel Cell by Suzer HexisSOFC fuel with a tubular structure

79

Hydrogen as a fuel

80

Fuel treatment

◼ H2: difficulty of storage and distribution network

◼ CH3OH: reforming process is a classical technology but remains costly

◼ Natural gas (CH4):

◼ Desulfuration

◼ Reforming

◼ Elimination of CO2 and of CO (except MCFC)

◼ Utilization of un reacted H2

◼ Compression: energy loss

◼ Opportunity for partial oxidation based systems

81

Hydrogen production paths

◼ Water electrolysis

◼ Environmental impact depends on the CO2 emission of electrical network

◼ Low overall efficiency (<60%)

◼ Advantages: enables a massive energy storage of electricity and allows to

level the production peeks

◼ Reforming of fossil fuel from natural gas or oil

◼ Production of CO2 and dependency to oil

◼ Emissions in upstream level

◼ Is considered as the best option currently

◼ Hydrogen « lost » in industrial processe (chemical industry in processes)

◼ Poly generation

◼ Production of heat, energy, and fuel in large scale energy systems. Possibility to perform Carbone capture & sequestration (CCS) as well as pollutants 82

CO2 and GHG emissions compared to the reforming in USA situation

Hydrogen production: GHG efficiency

83

Hydrogen production: the IPCC vision

84

Hydrogen route

85

Hydrogen network

86

Lighter than air

EST CE QUE L’HYDROGÈNE EST CARBURANT SUR?

Fuel tank

punctured

0 seconds

Fuel set on fire

3 seconds

Fuel tank

burning

60 seconds

87

Fuel leakage Simulation. Dr. Michael Swain.

Experiment on fuel leakage and burning car conducted with

the University of Miami at Coral Gables.

Hydrogen storages

88

Hydrogen storage

Specific energy Energy density

(Wh/kg) (Wh/l)

H2 compressed gas

(T amb. et p=20 Mpa)

33600 600

H2 liquefied

(T cryo. et p=0.1 Mpa)

33600 2400

Mg-H2 2400 2100

Vanadium hydride 700 4500

Methanol 5700 4500

Petrol 12400 9100

89

MECA0500: FUEL CELLS - Part 1: Fuel Cell...Fuel Cell - History In 1839 Christian Schönbein, a...

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